linux-kernel - Re: [PATCH 1/4] rust: fix signature of rust_fmt

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87eczio2c5.fsf@kernel.org>
Date: Fri, 28 Feb 2025 10:17:30 +0100
From: Andreas Hindborg <a.hindborg@...nel.org>
To: "Alice Ryhl" <aliceryhl@...gle.com>
Cc: "Greg Kroah-Hartman" <gregkh@...uxfoundation.org>,  "Miguel Ojeda"
 <ojeda@...nel.org>,  "Petr Mladek" <pmladek@...e.com>,  "Steven Rostedt"
 <rostedt@...dmis.org>,  "Andy Shevchenko"
 <andriy.shevchenko@...ux.intel.com>,  "Rasmus Villemoes"
 <linux@...musvillemoes.dk>,  "Sergey Senozhatsky"
 <senozhatsky@...omium.org>,  "Andrew Morton" <akpm@...ux-foundation.org>,
  "Boqun Feng" <boqun.feng@...il.com>,  "Gary Guo" <gary@...yguo.net>,
  Björn Roy Baron <bjorn3_gh@...tonmail.com>,  "Benno
 Lossin"
 <benno.lossin@...ton.me>,  "Trevor Gross" <tmgross@...ch.edu>,  "Maarten
 Lankhorst" <maarten.lankhorst@...ux.intel.com>,  "Maxime Ripard"
 <mripard@...nel.org>,  "Thomas Zimmermann" <tzimmermann@...e.de>,  "David
 Airlie" <airlied@...il.com>,  "Simona Vetter" <simona@...ll.ch>,
  <linux-kernel@...r.kernel.org>,  <rust-for-linux@...r.kernel.org>,
  <dri-devel@...ts.freedesktop.org>
Subject: Re: [PATCH 1/4] rust: fix signature of rust_fmt_argument

"Alice Ryhl" <aliceryhl@...gle.com> writes:

> On Fri, Feb 28, 2025 at 9:20 AM Andreas Hindborg <a.hindborg@...nel.org> wrote:
>>
>> "Alice Ryhl" <aliceryhl@...gle.com> writes:
>>
>> > Without this change, the rest of this series will emit the following
>> > error message:
>> >
>> > error[E0308]: `if` and `else` have incompatible types
>> >   --> <linux>/rust/kernel/print.rs:22:22
>> >    |
>> > 21 | #[export]
>> >    | --------- expected because of this
>> > 22 | unsafe extern "C" fn rust_fmt_argument(
>> >    |                      ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8`
>> >    |
>> >    = note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}`
>> >               found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}`
>> >
>> > The error may be different depending on the architecture.
>> >
>> > Fixes: 787983da7718 ("vsprintf: add new `%pA` format specifier")
>> > Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>
>> > ---
>> >  lib/vsprintf.c       | 2 +-
>> >  rust/kernel/print.rs | 8 ++++----
>> >  2 files changed, 5 insertions(+), 5 deletions(-)
>> >
>> > diff --git a/lib/vsprintf.c b/lib/vsprintf.c
>> > index 56fe96319292..a8ac4c4fffcf 100644
>> > --- a/lib/vsprintf.c
>> > +++ b/lib/vsprintf.c
>> > @@ -2285,7 +2285,7 @@ int __init no_hash_pointers_enable(char *str)
>> >  early_param("no_hash_pointers", no_hash_pointers_enable);
>> >
>> >  /* Used for Rust formatting ('%pA'). */
>> > -char *rust_fmt_argument(char *buf, char *end, void *ptr);
>> > +char *rust_fmt_argument(char *buf, char *end, const void *ptr);
>> >
>> >  /*
>> >   * Show a '%p' thing.  A kernel extension is that the '%p' is followed
>> > diff --git a/rust/kernel/print.rs b/rust/kernel/print.rs
>> > index b19ee490be58..8551631dedf1 100644
>> > --- a/rust/kernel/print.rs
>> > +++ b/rust/kernel/print.rs
>> > @@ -6,13 +6,13 @@
>> >  //!
>> >  //! Reference: <https://docs.kernel.org/core-api/printk-basics.html>
>> >
>> > -use core::{
>> > +use core::fmt;
>> > +
>> > +use crate::{
>> >      ffi::{c_char, c_void},
>> > -    fmt,
>> > +    str::RawFormatter,
>> >  };
>> >
>> > -use crate::str::RawFormatter;
>> > -
>> >  // Called from `vsprintf` with format specifier `%pA`.
>> >  #[expect(clippy::missing_safety_doc)]
>> >  #[no_mangle]
>>
>> The changes in this last hunk is not mentioned in the commit message.
>
> The diff is rendered pretty poorly, but this is just importing
> integers from crate::ffi instead of core::ffi, and I do believe that
> the commit message makes it clear that this is needed.

I see, thanks for clarifying. Consider including the clarification in
the commit message.


Best regards,
Andreas Hindborg